Transcript Constructions Vocabulary • Congruent-the same measurement • Construct-to create • Straightedge-any object you can use to make a straight line • Compass-an instrument used to.

Constructions
Vocabulary
• Congruent-the same measurement
• Construct-to create
• Straightedge-any object you can use to
make a straight line
• Compass-an instrument used to create
circles or parts of circles
• Arc-part of a circle that can be drawn
with a compass
Constructing Line
Segments
• Draw a line segment and label it AB
A
B
Constructing Line
Segments
• Use a straightedge to draw Ray PS so
it’s longer than AB
A
P
B
S
Constructing Line
Segments
• Place the endpoint in the circle of the safety
compass at A and the pencil point on B and
tighten down. Draw an arc.
A
P
B
S
Constructing Line
Segments
• Keep the same setting on the compass
and place the point at P. Draw an arc
that intersects PS at a new point Q.
A
B
P
Q
S
Constructing Congruent
Angles
• Draw an angle and label it PQR
P
Q
R
Constructing Congruent
Angles
• Use a straightedge to draw Ray ST
P
Q
R
S
T
Constructing Congruent
Angles
•
Place the point in the circle of the safety compass at vertex
Q. Set your measurement to 2 cm.Draw an arc that
intersects both sides of PQR to make points X and Y.
X
Q
Y
Constructing Congruent
Angles
• Keeping the same setting, place the point at S and
draw an arc that intersects ST. Label the
intersection Point A.
X
Q
Y
S
A
Constructing Congruent
Angles
• Place the compass so that the point is at X and first drawing
hole is at Y. Keep that setting and place the point at A. Draw
an arc that intersects the arc you drew in Step 3. Label that
intersection Point M.
X
Q
Y
S
A
Constructing Congruent
Angles
•
With the straightedge, draw Ray SM.
Angle MST is congruent to Angle PQR.
Compass Questions
• How does the compass work in copying
a line segment?
• Explain how the compass works in
copying an angle.
Bisecting Line Segments
• Draw a line segment and label it CD
Bisecting Line Segments
• Place the point of the compass at C.
Extend the runner until the first
drawing hole is more than halfway to D
and set it. Draw an arc “above” and
“below” CD.
Bisecting Line Segments
• Keeping the same setting, place the
point on D and draw another arc
“above” and another “below” for two
new points Q and R.
Bisecting Line Segments
• With a straightedge, draw the line
segment determined by the two new
points. This will intersect the original
line. Name the intersection Point M.
• What do you think bisect means?
• What type of angles are formed by
perpendicular segments?
Bisecting Angles
• Draw an angle and label it Angle ABC.
Bisecting Angles
• Place the point of the compass at B
and draw an arc that intersects both
sides of the angle. Label the points of
intersection X and Y.
Bisecting Angles
• Place the point of the compass at X
and move the runner to a length more
than halfway to Y. Draw an arc in the
interior of Angle ABC.
Bisecting Angles
• Keep that same setting and place the
point at Y and draw an arc that
intersects the arc you just drew. Label
the intersection T.
Bisecting Angles
• With a straightedge, draw Ray BT, this
is the bisector of Angle ABC.